dfu: Provide means to find difference between dfu-util -e and -R

This commit provides distinction between DFU device detach and reset.
The -R behavior is preserved with proper handling of the dfu-util's -e
switch, which detach the DFU device.

By running dfu-util -e; one can force device to finish the execution of
dfu command on target and execute some other scripted commands.

Moreover, some naming has been changed - the dfu_reset() method now is known
as dfu_detach(). New name better reflects the purpose of the code.

It was also necessary to increase the number of usb_gadget_handle_interrupts()
calls since we also must wait for detection of the USB reset event.

Example usage:
1. -e (detach) switch
 dfu-util -a0 -D file1.bin;dfu-util -a3 -D uImage;dfu-util -e

 access to u-boot prompt.

2. -R (reset) switch
 dfu-util -a0 -D file1.bin;dfu-util -R -a3 -D uImage

 target board reset

Signed-off-by: Lukasz Majewski <l.majewski@samsung.com>
Reviewed-by: Stephen Warren <swarren@nvidia.com>
Tested-by: Stephen Warren <swarren@nvidia.com>

common/cmd_dfu.c

@@ -15,6 +15,8 @@
 
 static int do_dfu(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
 {
+	bool dfu_reset = false;
+
 	if (argc < 4)
 		return CMD_RET_USAGE;
 
@@ -36,17 +38,28 @@ static int do_dfu(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
 
 	int controller_index = simple_strtoul(usb_controller, NULL, 0);
 	board_usb_init(controller_index, USB_INIT_DEVICE);
-
+	dfu_clear_detach();
 	g_dnl_register("usb_dnl_dfu");
 	while (1) {
-		if (dfu_reset())
+		if (dfu_detach()) {
+			/*
+			 * Check if USB bus reset is performed after detach,
+			 * which indicates that -R switch has been passed to
+			 * dfu-util. In this case reboot the device
+			 */
+			if (dfu_usb_get_reset()) {
+				dfu_reset = true;
+				goto exit;
+			}
+
 			/*
 			 * This extra number of usb_gadget_handle_interrupts()
 			 * calls is necessary to assure correct transmission
 			 * completion with dfu-util
 			 */
-			if (++i == 10)
+			if (++i == 10000)
 				goto exit;
+		}
 
 		if (ctrlc())
 			goto exit;
@@ -58,9 +71,11 @@ exit:
 done:
 	dfu_free_entities();
 
-	if (dfu_reset())
+	if (dfu_reset)
 		run_command("reset", 0);
 
+	dfu_clear_detach();
+
 	return ret;
 }
 

drivers/dfu/dfu.c

@@ -17,20 +17,41 @@
 #include <linux/list.h>
 #include <linux/compiler.h>
 
-static bool dfu_reset_request;
+static bool dfu_detach_request;
 static LIST_HEAD(dfu_list);
 static int dfu_alt_num;
 static int alt_num_cnt;
 static struct hash_algo *dfu_hash_algo;
 
-bool dfu_reset(void)
+/*
+ * The purpose of the dfu_usb_get_reset() function is to
+ * provide information if after USB_DETACH request
+ * being sent the dfu-util performed reset of USB
+ * bus.
+ *
+ * Described behaviour is the only way to distinct if
+ * user has typed -e (detach) or -R (reset) when invoking
+ * dfu-util command.
+ *
+ */
+__weak bool dfu_usb_get_reset(void)
 {
-	return dfu_reset_request;
+	return true;
 }
 
-void dfu_trigger_reset()
+bool dfu_detach(void)
 {
-	dfu_reset_request = true;
+	return dfu_detach_request;
+}
+
+void dfu_trigger_detach(void)
+{
+	dfu_detach_request = true;
+}
+
+void dfu_clear_detach(void)
+{
+	dfu_detach_request = false;
 }
 
 static int dfu_find_alt_num(const char *s)

drivers/usb/gadget/f_dfu.c

@@ -372,7 +372,7 @@ static int state_dfu_idle(struct f_dfu *f_dfu,
 		to_runtime_mode(f_dfu);
 		f_dfu->dfu_state = DFU_STATE_appIDLE;
 
-		dfu_trigger_reset();
+		dfu_trigger_detach();
 		break;
 	default:
 		f_dfu->dfu_state = DFU_STATE_dfuERROR;

include/dfu.h

@@ -150,11 +150,14 @@ struct dfu_entity *dfu_get_entity(int alt);
 char *dfu_extract_token(char** e, int *n);
 void dfu_trigger_reset(void);
 int dfu_get_alt(char *name);
-bool dfu_reset(void);
+bool dfu_detach(void);
+void dfu_trigger_detach(void);
+void dfu_clear_detach(void);
 int dfu_init_env_entities(char *interface, char *devstr);
 unsigned char *dfu_get_buf(struct dfu_entity *dfu);
 unsigned char *dfu_free_buf(void);
 unsigned long dfu_get_buf_size(void);
+bool dfu_usb_get_reset(void);
 
 int dfu_read(struct dfu_entity *de, void *buf, int size, int blk_seq_num);
 int dfu_write(struct dfu_entity *de, void *buf, int size, int blk_seq_num);